In a process for manufacturing a semiconductor device including semiconductor elemental devices, such as a transistor, a lithography technique is used to realize miniaturization of patterns. As one of the challenges this lithography technique faces, there is a need to improve overlay accuracy between layers.
In light of this, there is a conventional technique of radiating femtosecond laser into the glass of a photomask to alter the glass and thereby to correct mask pattern positions. In this mask pattern correction by use of irradiation with femtosecond laser, it is required to perform the correction with high accuracy in a short time.